The present invention relates to a novel process for making substituted or unsubstituted polyphenyls. More particularly, this invention relates to the dehydrogenation of cyclohexylbenzene to biphenyl.
There are many known methods for manufacturing polyphenyls. Among these methods is the thermal dehydrogenation of benzene and the partial oxidation of benzene. However, it is well known to those skilled in the art that higher molecular weight aromatics, typified by biphenyls and terphenyls, may be difficult to prepare in high purity because of their high boiling points which preclude distillation at reasonable temperatures and pressures. Furthermore, it may be difficult to attain these materials in high purity because many techniques by which they may be recovered give undesirable yields of byproducts or require very severe processing conditions. Thus, it is very important to develop a process for producing polyphenyls which is very selective with high conversions.
The present invention relates to a novel process for producing substituted and unsubstituted polyphenyls from the corresponding substituted and unsubstituted cyclohexylbenzenes. This process can be carried out in a simple and straightforward manner to yield the desired end products with extremely high selectivities and conversions. In fact, by using the process disclosed in the instant invention, selectivities approaching 100% are obtained.